Unit-III Traction
Special features of Traction motors, selection of Traction Motor, Different system of electric traction and their Advantages and disadvantages, Mechanics of train movement: simplified speed time curves for different services, average and schedule speed, tractive effort, specific energy consumption, factors affecting specific energy consumption, acceleration and braking retardation, adhesive weight and coefficient of adhesion,

UNIT IV TRACTION MOTORS

DC motors, single phases and three phases motors, starting and control of traction motors, braking of traction motors: plugging, rheostatic and regenerative braking, Modern 25 KV a.c. single phase traction systems: advantages, equipment and layout of 25 KV, line and current selection, single phase power frequency A.C. traction.